Manufacture of decorative plastic



March 12, 1935. A. T. BAILEY 1,994,164

MANUFACTURE OF DECORATIVE PLASTIC Filed Sept 2, 1933 INVENTOR ALBERT T. BA'lLEY ATTORNEY Patented Mar. 12, 1935 1,994,164

1,994,164 MANUFACTURE OF DECORATIVE PLASTIC Albert Tanner Bailey, Montclair, N. J., assignor to Dupont Viscoloid Company," Wilmington,

Del., a corporation of Delaware Application September 2, 1933, Serial No. 687,963 s Claims. (01. 18-59)" UNITED STATES PATENT OFFICE This invention relates to the manufacture of embryo rod into a finished rod. In particular decorative plastic, more particularly decorative accordancewith the invention, the envelop is itcellulosic plastic in the form of rods havingadecoself of thermoplastic material so that in the rative design, or. pattern, incorporated therein. process it becomes permanently united with the Such rods have the pattern extending longituindividual rods of plastic, and thus becomes an 5 dinally therethrough at right angles to the spread integral'portion of the final rod. During the opof the pattern, thus adapting the rods to be erations theindividual elements become thoroughsevered diametrically across into discs usable for 1y united into a unitary structure. Furthermore, buttons, for example. by varying the number of individual rods, their It has heretoforebeen proposed to produce specific character as regards their distinguishing 1 items of the general character indicated by asrelationship, e. g. color, opacity, transparency, sembling units of plastic into an embryo rodand etc., and the distinguishing relationship of the then uniting the units either by extruding the emplastic envelop, an almost limitless variety of debryo rod, or by severing the embryo rod into discs signs may be produced.

and uniting the portions of each individual disc by Without restricting the invention thereto it is 15 subjecting the disc to a molding operation. These described with more particular reference to the processes,: requiring, as they do, the utilization of accompanying drawing in which: Fig. 1 is a perextrusion or of molds, embody certain complicaspective view of individual rods assembled into tions that it is desirable to eliminate.- I have an embryo rod; Fig. 2 is a longitudinal cross secdevised a process by which individual rods inition of the envelop with the embryo rod, illus- 20 tially assembled to give an embryo rod displaying trated in Fig. 1, received therein; Fig. 3 is an the desired pattern, are united into a finished enlargeddiametricalcross-section taken substanproduct without the necessity of extrusion or tially on the line 3-3 of Fig. 2 and showing the molding; and, furthermore, this process provides appearance of the entire embryorod, including for the utilization, as a unit of the uniting appatherein the envelop, before application of the con- 5 ratus, of a portion of the plastic that is to become solidating temperature and pressure; Fig. 4 is an embodied in the rod. Also the process provides end View of the consolidated rod after its subfor the production of a substantially limitless jecting to temperature and pressure, thus giving variety of designs, readily and inexpensively. the final rod; Figs. 5 to 9 inclusive are illustrations One object of the invention is to provide a of various designs produced in accordance with the 30 process for the manufacture of patterned plastic process; Fig. 10 is a view similar to Fig. 3 but stock, for example rods. A further object is to showing the assembled individual rods received provide such a process wherein a portion of the in an envelop of a material and character, e. g. plastic destined for incorporation in the rod is a rubber bag, not intended for uniting with the utilized as an apparatus feature in the practice individual rods; and Fig. 11 is an end view of the 35 of the process. A further object is to provide plasrod produced when operating with the rubber bag tic stock for use in the production of e. g. buttons, of Fig. 10. As is evident, the figures of the drawchecks, etc. Afurther object is to provide deCoraing are to various scales. In Figures 4 to 9 and tive buttons, checks, etc. To these ends and also 11, the cross lining is to indicate difierence in the to improve generally upon processes and articles appearance of difierent portions, as difierences in 40 of the general characterindicated, my invention color, and not to indicate cross sectioning. consists in thevarious matters hereinafter de- Without restriction of the invention thereto, scribed and claimed. a the production of a rod of cellulose nitrate plas- In general, these objects are accomplished by tie in accordance with the invention will serve 5 assemblying into an embryo rod, a number of as a specific example. The material is cellulose 5 rods of thermoplastic material, e. g. cellulosic nitrate plastic of any preferred, or standard complastic, to present a desired pattern extending position, e. g. (parts by weight) cellulose nitrate crosswise of the embryo rod and longitudinally 100, camphor 33, ethyl alcohol .(formula 2B) 63. therethrough, the individual rods having adis- From this material are produced, by methods tinguishing relationship among themselves, for well known in the art, e. g. extrusion, seven rods 50 example having different colors, to produce the and a tube or envelop, and the solvent content pattern; and the embryo rod is then introduced therein is reduced to a small amount, but sufiiinto an envelop, the envelop evacuated, and the cient to assist in the adhesion of the elements each assembly subjected to hydraulic pressure and to to the other under temperature and pressure.

temperature in order to unite the elements of the The plastic may of course include such coloring 55 matter and stabilizer as is desired. In the present instance the consolidated rod, and hence the discs or buttons to be severed therefrom, embodies six opaque items surrounding, and surrounded by, transparent plastic. Thus, referring to Figs. 1 to 4 inclusive, there are a central transparent rod 1, six opaque, e. g. white, rods 2 and a transparent border 3. I

The rods 1 and 2 are bundled together as indicated in Fig. 1 and, for convenience in handling and to initially fix the embryo design, are attached to each other. This is conveniently done by holding the rods in contact-and dipping one end of the bundle in a suitable cement having as one of its ingredients a solvent for the plastic, for an inch or two; removing the excess solvent and allowing the dipped portions of the bundle to dle for its whole length in a solvent; and withdrawing the bundle and allowing it tostand in an upright position long enough to allow it to dry sufiicientlyto permit handling at room temperature. In dipping the rods it is important that the cement come in contact with all surfaces. As a medium for cementing. purposes ordinary commercial ethyl acetate is satisfactory, and with ethyl'acetate I have found it satisfactory to dip the rods for about two or three seconds, theoriterion for the dipping time being simply a thorough wetting of the rods.

A tube4 of transparent cellulose nitrate plastic such as that of the rods, and with one end sealed as at 5 is provided, of an inside diameter slightly greater than the maximum diameter of the rod assembly, and the bundle of rods is introduced therein. The length of the tube. is such as to provide for the sealed end 5, and the portion 6 of sufficient length to permit of its ultimate sealing also. If desired, of course, the sealing at 5 may be carried out after the introduction of the bundle, rather than before; and, in either case may be done in any suitable way as by coating the interior wall of the tube with a suitable cement,- e. g. pyroxylin-containing solution, and then subjecting the tube to heat (as on a hot plate) and squeezing the ends of the tube together. After the introduction of the bundle the interior wall of the open end 6 of the tube is then coated with cement up to the adjacent end of the bundle of rods. The tube is then stoppered as with a rubber. stopper '7, there being a sufficient length of tube. between the stopper and the adjacent end of the bundle of rods to permit the sealing of the tube by the collapsing thereof as along the line a-a. The stopper 7 is provided with an e. g. glass tube 8 for the exhaustion of air from the tube 4. Desirably the stopper is inserted while the cement, with which the interiorof the end 6of the tube 4has been coated, is soft, in order to insure an effective seal between the stopper and the walls of the tube.

The glass tube is now connected with a vacuum line and the tube 4 immersed, starting with the end 5, in a bath of hot water to a distance approximately one inch below the top (stopperadjacent) end of the bundle of assembled rods, the water being suffioiently hot to soften the tube. As the tube is evacuated the walls collapse against the sides of therods and the tube may then be lowered entirely into the water so as to continue the evacuation and to collapse the walls of the tube above the upper end of the rods. Thiscollapsing seals thestoppered end by the walls of the tube adhering to each other; approximately at the line aa. The whole assembly is then removed from the hot water tank and. the tube severed between the sealing and the stopper. The assembly is then allowed to cool. There results the bundle of rods surrounded along its entire' length with the tube 4 entirely sealed at both ends to give a closed envelop containing the bundle of rods, the, tube 4 being-in close and intimate contact with the adjacent side surfaces of the rods 2.

- The assembly is now subjected to a temperature sufficient to soften the plastic, and a pressure to thoroughly consolidate the items and cause their permanent uniting into an integral mass. Conveniently this is done by immersing the assembly 'in a container or gun provided with means for introducing hot water under hydraulic pressure, such apparatus being well known in the art. The-temperature of the water and the pressure to which plastic stock should be subjected to insure thoroughunitingthereof. willlof icourse v vary. with particular conditions but'will iniany case be evident to those skilled-intheart. I have found thatthe subjectionof the assembly towater at a temperature of 200 F., under 3,000

may be subjected, to seasoning for the purposes of removing any absorbed waterfrom' the surface, or for the removalofsolvent used in connection with the dipping of the assembledrodsEILandJ-2,

.all as will be understood byz-those skillediinzithe art. Seasoning may be omitted if sodesired, the desirability of seasoning in any. particular .case depending, of j course, entirely upon; the .use' of the discs or buttons to be severed from the-fin:- ished rod. The overhangs at 5.and;6.areiof course severedfrom the mass .attheaendof the assembly of rods.

The pressure to which the assembly is sube jected forces the units into intimate contact and closes and fills all interstices.,therebetween. The particular shape of the initialtrods land 2, their number, and the particular arrangement in which they are bundled influence the shapes. that .the particular units ultimately acquire; so -thatlby varying these factors differences in the :flna'l shapes of the units maybe readily arrive'duat.

For example-Fig. 4 substantially.illustrates-the shapes obtained when using the seven cylindrical rods as described. above; and in this case-.all of the rods had substantially'the .same; solvent content, so thatthey wereequallyaffecteduby the temperature and pressure. bining in the sameassemblyrodsof I seasoned; partially seasoned, and/or unseasoned'material, so that some rods are renderedrsofter byaigiventemperature than are others. the changingof'the shapes of certain of the rods ,(due to their greater softness) to a greater-degree than the shapeszof others are changed maybe controlled. It will be understood by those skilled in the art that-.when material less than thoroughly seasoned is. used; the strength of the cement used-in theassembly of the rods should, of coursegbe altered as well as the time of dipping the rods; or, in: other words the less the rods are seasoned, and therefore the more the solvent they contain, the-less .can -be the strength ofv the cement. Also-asthe amount Obviously, 'byticom,

of seasoning ,is increased the temperatureand pressure may need to.be-increase.d,.as

In referring to seasoned, partially seasoned and funseasoned stock it will be, of course, un-

derstood by those skilled in the art that these terms are used, in the artnwith a considerable degreeof flexibility. Generally speaking, however, seasoned stock has a solvent content of say,

2 to 4%, unseasoned stock has a solvent content of approximately 8to' 12%, and, partially seasoned stock has an intermediate solvent content.

When the above detailed process is used for the production of buttons of approximately one inch in diameter I have found it convenient to use rods 1 and 2 about .237 inch in diameter, and about 30 inches in length. The tube 4 is, as stated above, of slightly greater interior diameter than the rod assembly; has a wall thickness suiiicient to bring the entire assembly up to a diameter slightly greater than the desired finished diameter of the buttons (in order to allow for shrinkage due to seasoning); and may have an overlap at the end 6 of approximately three inches. It will be understood that upon the completion of the consolidated rod it is severed crosswise into discs or buttons. These discs may be subjected to such further treatment as is desired, such as polishing, the punching of thread holes, etc. Although the discs as severed from the rods are thoroughly welded and consolidated, so that molding for the purpose of integrating the discs is unnecessary, the discs may be molded if for any purpose it be desired.

As illustrating further possibilities of design, reference is made to Figs. 5 to 9 inclusive; but it will be understood that a very great number of designs in addition to those here illustrated, may be produced by the process. Fig. 5 illustrates the results of a combination of seasoned and partially seasoned rods, the rods 9 having been more thoroughly seasoned than the rods 10 (and the mass also including tubing 12). In Figs. 6 and '7 are illustrated the results of the use of a combination of seasoned rods with unseasoned tubing, the rods being designated as 11 and the tubing being designated as 12. In Fig. 8 is illustrated an effect produced'by combining sheet stock with rods and a tube, the sheet stock being designated as 13, the rods 14 and tube 15. The process is obviously not confined to the production of circular outlines but is adapted to the production of other shapes as Well, this being illustrated in Fig. 9 showing the effect obtained by using a central triangular bundle of three rods surrounded by two tubes.

While the process has been above described as including the utilization, and embodiment in the ultimate consolidated rod, of an envelop of thermo plastic material, certain advantageous features of the process may be practiced without the essential inclusion. of this feature. Thus, as illustrated in Fig. 10 the envelop 16 may be of a material adapting it for use as an envelop merely, e. g. it may be a rubber bag. The bag will be used as is the plastic tube 4 except that, being of material not adapted to be permanently adherent to the thermo plastic rods, it will not become permanently consolidated therewith and will ultimately be stripped therefrom. In Fig. 11 is shown a rod section, or button, produced in this manner. If desired, or course, the entire assembly, 1. e. the tube 4 and the bundle of rods 1 and 2, may be enclosed in a rubber bag for the combining or compositing operation, but I have not found such a procedure of particular advantage.

While nitrocellulose plastic has been more particularly. referred to above, it will be understood that other thermo plastic materials may be used the practice of the process, e. g. plastics of other :cellulose esters e. g., cellulose acetate, and plastics of cellulose ethers, e. g. ethyl cellulose and benzyl cellulose; and also thermo plastic resins as synthetic resins of the vinyl acetate, acrylic acid esters, methacrylic acid esters, polyhydric alcoholpolybasic acid (glyptal), styrol, and derivatives of vinyl acetate (e. g. interpolymers with aldehydes), types. Furthermore, in certain cases some of the units may be of one plastic, and others of the units of a different plastic, in the same assembly, care being taken, of course, that solvents, cements, and specific plastics are compatible with each other to the end of securing proper welding and permanent adhesion between the various units.

It will be understood that while the use of cylindrical rods ordinarily recommends itself, rods of a cross section other than circular may be used if desired; and, furthermore, the tubes may be of varying cross sectional shapes.

I claim: v

1. The method of producing a patterned thermoplastic body in the character of a rod having a pattern spread crosswise thereof and extending longitudinally therethrough which method comprises, forming a bundle of thermoplastic bodies of distinguishing relationship: to present elements of the pattern spread crosswise of the bundle, surrounding the bundle with an envelope of thermoplastic: material, and subjecting the entire assembly to heat and. direct fluid pressure to consoli date said assembly into a unitary rod-like body, with the enveloping body thus completing the pattern.

2. The method of producing a patterned cellulosic derivative plastic body in the character of a rod having a pattern spread crosswise thereof and extending longitudinally therethrough which method comprises, forming a bundle of cellulosic derivative plastic bodies of distinguishing relationship to present elements of the pattern spread crosswise of the bundle, surrounding the bundle With an envelope of cellulosic derivative plastic, and subjecting the entire assembly to heat and direct fluid pressure to consolidate said assembly into a unitary rod-like body, with the enveloping body thus completing the pattern.

3. A method as recited in claim 2 in which at least one of the cellulosic derivative plastic units is of cellulose ester plastic.

4. A method as recited in claim 2 in which at least one of the cellulosic derivative plastic units is of cellulosic ether plastic.

5. A method as recited in claim 2 in which at least one of the cellulosic derivative plastic units is of cellulose nitrate plastic.

6. A method as recited in claim 2 in which at least one of the cellulosic derivative plastic units is of cellulose acetate plastic.

7. The method of producing a patterned thermoplastic body in the character of a rod having a pat-tern spread crosswise thereof and extending longitudinally therethrough which method com- 'tegral therewith and thus completing the pattern. body and of the envelop being of 8. The method of producing a patterned therrelationship with respect to each other, and submoplastic body in the character of a rod having jeoting the entire assembly to'heat and'direct' fluid apattern spread crosswise thereof and extending pressure to consolidate said assembly into a. unilongitudinally therethrough which method c0m tary rod-like body, with the enveloping body com- I: 5

prises, assembling a central rod-like body of bined with the central body to present thepattern. thermoplastic materialand a surrounding envelop of thermoplastic material, the materials of the ALBERT TANNER BAILEY,v 

